The present invention is directed to a cooling device for electrical assemblies for mounting on a carrier.
The development of more and more powerful electronic assemblies also makes high demands of the cooling technology. A number of concerns are thereby raised in addition to the optimum heat elimination:
(1) The structure should be modular and flexible, i.e. assemblies other than those originally provided should be capable of being mounted. Given the increase in dissipated power, which derives, for example, due to higher performance data, the cooling unit should be adaptable to the new demands without involved modifications. Modifications of a mechanical nature (for example, housing dimensions, fastening capability) should also be taken into consideration.
(2) Manipulation in assembly and disassembly should be simple, for example when replacing assemblies during the course of a repair.
(3) An electrical insulation between the assemblies and the cooling system should be possible with simple means.
(4) Problems with the electrochemical compatibility of the material through which flow is conducted should be avoided.
(5) Finally, the cooling system should be low cost.
Conventional liquid coolers satisfy these demands relatively inadequately in practice. An integration of cooling channels in the assemblies themselves is standard. This, however, is involved and problematical in the assembly or, respectively, disassembly of the assemblies. The cooling water connections must be parted in the disassembly of the assemblies, whereby, in particular, care must be exercised to see that cooling water does not come into contact with voltage-carrying parts. Particular precautions must there for be taken. Such precautions, however, are time consuming and expensive and serve to complicate manipulation. This problem can only be inadequately solved with quick-acting closures for the water management since such quick-acting closures have considerable disadvantages in terms of dead space volume, tightness, pressure loss and costs.
German Published Application 1 439 308 discloses a cooling arrangement wherein a transistor is screwed onto a cooling member that is mounted on a carrier. Cooling channels through which air flows proceed through the cooling member. A printed circuit board is provided on that side of the transistor lying opposite the cooling member.
DE 35 31 729 C2 discloses a cooling device wherein electronic components are arranged on a ceramic plate. For heat elimination, the side of the ceramic plate facing away from the equipment side is provided with pins by which heat is output to the ambient air that flows past. Since the ceramic plate distributes heat well, the temperature difference between the various pins is slight and the heat elimination into the air is efficient.